Seismic interpretation of the Cantabrian platform around “Le Danois Bank”, Bay of Biscay

Résumé

A set of high quality seismic reflection data has been interpreted integrating them with previous geological and geophysical studies in the area of “Le Danois Bank” a structural high situated at the north Iberian margin, in the Bay of Biscay. Old borehole information together with digitalization of sonic logs permits a 3D model of geological surface as and its conversion to depth in the Meso-Tertiary basin of the Asturian platform providing new insigths into the geodynamical evolution of this margin. The structural features observed in the seismic lines are the result of three main tectonic events related to the Iberian plate paleogeographic evolution since the Permian: 1) normal faults and asymmetric basins from Permian to Cretaceous extensional stage; 2) upper Cretaceous sediments linked to the passive margin period; 3) inverted normal faults an related folds developed during compressive phase. Onshore data show that both the Mesozoic extension and the alpine compression decrease westward. Offshore, there are detailed studies of the easternmost part, but there is a lack in the westernmost, where the structure is not well-known. The data used in this study provides a better image of the basin, allowing a more accurate interpretation of the central segment.